CN114929498B

CN114929498B - Fuel tank

Info

Publication number: CN114929498B
Application number: CN202180008187.8A
Authority: CN
Inventors: 中屋和成; 诸冈和义; 三桥宽也
Original assignee: Yachiyo Industry Co Ltd
Current assignee: Yachiyo Industry Co Ltd
Priority date: 2020-01-31
Filing date: 2021-01-13
Publication date: 2023-05-26
Anticipated expiration: 2041-01-13
Also published as: EP4098423A4; WO2021153226A1; JP7153146B2; EP4098423A1; US20230050517A1; EP4098423B1; JPWO2021153226A1; US11628721B2; CN114929498A

Abstract

A fuel tank of the present invention has a built-in member (6), the built-in member (6) having a head portion (6 d), a neck portion (6 c) and a shoulder portion (6 b), wherein the built-in member (6) is fixed to a tank body by wrapping a parison around the neck portion (6 c) at the time of molding the tank body, a hollowed-out portion (6 k) opening to the end face side of the head portion (6 d) is formed in the head portion (6 d) and the neck portion (6 c), and the fuel tank has an end cap member (6 e) sealing the opening of the hollowed-out portion (6 k).

Description

Fuel tank

Technical Field

The present invention relates to a fuel tank.

Background

There is known a method of attaching a component such as a valve to a blow-molded article such as a fuel tank of an automobile as a built-in member. For example, patent document 1 describes a method for manufacturing a fuel tank having a built-in member including a head, a neck, and a shoulder. In this method for manufacturing a fuel tank, air is introduced from the outside of a parison during molding of a tank body to shape the parison along the neck, thereby fixing a built-in member to the tank body. In this case, the air around the neck is discharged to the tank body side by using the hole communicating from the neck to the tank body.

Prior art literature

Patent literature

Patent document 1: international publication No. 2018/225413.

Disclosure of Invention

Technical problem to be solved by the invention

In order to improve the fixing strength of the built-in member, it is effective to enlarge the diameters of the head and neck. In order to prevent a void from being generated during molding, the insert member is required to have a hollow portion, instead of a solid portion, of the head and neck portion. However, in the case of hollowing out the end face opening of the head, the parison enters the hollowing out portion when the parison is fixed to the tank main body. If the parison intrudes into the hollowed-out portion, there are problems such as uneven thickness of the parison and breakage of the barrier layer.

The present invention has been made in view of the above, and an object of the present invention is to prevent a parison from entering into a hollowed-out portion formed in a head and a neck of a built-in member.

Technical scheme for solving technical problems

In order to solve the above-described problems, a fuel tank according to the present invention includes a built-in member having a head, a neck, and a shoulder, wherein the built-in member is fixed to a tank body by wrapping a parison around the neck when the tank body is molded, and a hollowed-out portion that opens toward an end face side of the head is formed in the head and the neck, and the fuel tank includes an end cap member that seals an opening of the hollowed-out portion.

According to the present invention, by providing the end cap member in the opening of the hollowed-out portion, it is possible to prevent the parison from entering the hollowed-out portion formed in the head and neck during molding, and therefore, it is possible to suppress the thickness unevenness of the parison and prevent the barrier layer from breaking.

Further, it is preferable that a first communication portion communicating with the outside and the hollowed portion is formed in the neck portion, a second communication portion communicating the hollowed portion with the inside of the case main body is formed in the shoulder portion, and air outside the neck portion flows into the inside of the case main body through the first communication portion and the second communication portion. With this configuration, the air around the neck portion can be discharged to the tank body side, and thus the parison can be reliably shaped around the neck portion.

In addition, it is preferable that a plurality of the hollowed-out portions are formed, and a third communication portion communicating with each other is formed adjacent to the hollowed-out portions. With this configuration, the air around the neck can be more efficiently discharged into the case main body through the first communication portion, the second communication portion, and the third communication portion.

Effects of the invention

The invention relates to a fuel tank which can prevent parison from invading into a hollowed-out part formed on a head and a neck.

Drawings

Fig. 1 is a schematic cross-sectional view of a fuel tank according to an embodiment of the present invention.

Fig. 2 is an external perspective view of the built-in member.

Fig. 3 is a front view of the built-in member.

Fig. 4 is a top view of the insert member.

Fig. 5A is a cross-sectional view of the insert member.

Fig. 5B is a B-B cross-sectional view of the insert member.

Fig. 6 is an enlarged perspective view of the built-in member.

Fig. 7 is a schematic longitudinal sectional view of the fuel tank manufacturing apparatus.

Fig. 8 is a view for explaining a transfer state of a parison around an end portion of the built-in member at the time of molding.

Fig. 9 is a diagram for explaining a transfer state of the parison around the end of the built-in member at the time of molding.

Fig. 10 is a diagram for explaining a method of manufacturing a fuel tank in a fuel tank manufacturing apparatus, in which (a) represents a parison injection step, (b) represents a built-in member insertion step, and (c) represents a temporary built-in member installation step.

Fig. 11 is a diagram for explaining a method of manufacturing a fuel tank in a fuel tank manufacturing apparatus, in which (a) represents a closing step of a molding die, (b) represents a blow molding step, (c) represents a cooling step of a parison, and (d) represents an opening step of the molding die.

Detailed Description

Fuel tank according to embodiments

The fuel tank T shown in fig. 1 is mounted on a moving tool such as an automobile, a motorcycle, or a ship, and is mainly composed of a tank main body Ta and a built-in member 6. As shown in fig. 1, in the present embodiment, a columnar reinforcing member for maintaining the strength of the fuel tank T is exemplified as the built-in member 6, but the built-in member 6 may be a valve, a surge eliminating plate, or the like. In the following description, "up and down", "left and right" are indicated by arrows in fig. 1. This direction is defined for convenience of description and is not limiting of the invention. The left-right direction in fig. 1 corresponds to the opening and closing directions of a pair of molding dies for manufacturing the fuel tank T.

The tank body Ta is a hollow container made of resin for storing fuel such as gasoline, and has a multilayer structure including a barrier layer, for example. The case main body Ta is mainly made of a thermoplastic resin such as polyethylene or high-density polyethylene. The box body Ta is molded by, for example, blow molding.

The structure of the built-in member 6 will be described with reference to fig. 2 to 6. As the built-in member 6, any material (for example, thermoplastic resin such as PE (polyethylene)) that can be welded to the parison S (see fig. 7) that is a precursor of the tank main body Ta, or any material (for example, POM) that cannot be welded to the parison S that is a precursor of the tank main body Ta may be used. The parison S has a multilayer cross-sectional structure made of HDPE (high density polyethylene), EVOH (ethylene vinyl alcohol copolymer), an adhesive layer, and the like.

As shown in fig. 2, the built-in member 6 includes: a body portion 6a;

shoulders

6b, 6b formed at both ends of the trunk portion 6a;

neck portions

6c, 6c formed outside the

shoulder portions

6b, 6b; and

heads

6d, 6d. The built-in member 6 has a mirror-like structure in the left-right direction (up-down direction on the paper). Therefore, unless explicitly stated herein, only one side is described. In the description of the built-in member 6, the surface facing the body portion 6a side is referred to as "back surface", and the surface opposite to the "back surface" is referred to as "front surface".

The trunk portion 6a shown in fig. 2 is a portion that becomes a main body of the built-in member 6. The trunk portion 6a has a cylindrical shape, and a distal end portion thereof has a shape that expands in a direction toward the shoulder portion 6 b. A plurality of pillar weight reducing holes 6g are formed in an end portion of the trunk portion 6 a. The pillar weight-reducing hole 6g is a hole communicating with the communicating portion 6h (fig. 5B) and the tank main body Ta. The pillar weight reducing holes 6g are portions through which air flows when welding the parison S to the inner member 6, which will be described later.

The shoulder 6b shown in fig. 2 is a portion covering the recess 3d of the first molding die 3 or the recess 4d of the second molding die 4 shown in fig. 7. The shape and size of the shoulder 6b are not particularly limited as long as they can cover the

recesses

3d, 4 d. The shoulder portion 6b has a thin disk shape, and as shown in fig. 3, the outer diameter rb of the shoulder portion 6b is larger than the outer diameter ra of the trunk portion 6 a.

The neck 6c shown in fig. 2 is a portion connecting the shoulder 6b and the head 6d, and has a smaller diameter than the shoulder 6b and the head 6d as shown in fig. 3. The neck 6c is provided upright from the surface 6f of the shoulder 6b, and has a columnar shape. Roundness (R) is formed at the corner portion constituted by the shoulder portion 6b and the neck portion 6c and at the corner portion constituted by the head portion 6d and the neck portion 6 c.

As shown in fig. 2, six communication portions (first communication portions) 6m are formed in the neck portion 6c in the circumferential direction. The communication portion 6m is a hole that communicates the outside of the neck portion 6c with the hollowed portion 6k (see fig. 5A). The communication portion 6m functions as an exhaust path for exhausting air in the gap 6j when the parison S enters the gap 6j (described later) during molding. The shape, number, and the like of the communication portions 6m are not particularly limited as long as they can discharge air.

The head 6d shown in fig. 2 has a disk shape of a thick plate thicker than the shoulder 6 b. Here, the relationship between the thicknesses of the shoulder portion 6b and the head portion 6d is merely an example, and the shoulder portion 6b may be formed thicker than the head portion 6d. As shown in fig. 3, the outer diameter rd of the head portion 6d is larger than the outer diameter rc of the neck portion 6c and smaller than the outer diameter rb of the shoulder portion 6 b. Due to such a shape, a gap 6j is formed between the shoulder 6b and the head 6d, with the neck 6c as a bottom. The gap 6j is a portion into which the parison S enters during molding.

The shape and size of the head 6d are not particularly limited as long as the built-in member 6 can be fixed to the box main body Ta (see fig. 1) by entering around the head 6d and the neck 6c through the parison S. The portion corresponding to the parison S around the neck portion 6c is referred to as a "parison corresponding portion W" (see fig. 9).

The end cap member 6e shown in fig. 2 is mounted on the end surface of the head portion 6d, and seals the opening (see fig. 4) of the hollowed-out portion 6k. The end cap member 6e seals the opening of the hollowed-out portion 6k, and thus can prevent the parison S from penetrating into the hollowed-out portion 6k during molding. The material of the end cap member 6e is not particularly limited, but in the present embodiment, it is formed of the same material as the built-in member 6, for example.

As shown in fig. 4, a plurality of hollowed-out portions 6k are formed in the head portion 6d and the neck portion 6 c. The hollowed-out portion 6k is open at an end face of the head portion 6d, and is hollow from the head portion 6d to the neck portion 6 c. In the present embodiment, the opening of the hollowed-out portion 6k is sealed by the end cap member 6 e.

As shown in fig. 5A, the end cap member 6e is constituted by a cap portion 6e1 and a leg portion 6e2. When the cover portion 6e1 is placed so as to seal the opening of the hollowed portion 6k, the leg portion 6e2 is inserted into the hollowed portion 6k and engaged. The leg portion 6e2 is engaged with the hollowed portion 6k, so that the cover portion 6e1 can be fixed while preventing the cover portion 6e1 from rotating.

The lid portion 6e1 is configured to have a flat surface, and plays a role of preventing the parison S and the like from flowing into the hollowed portion 6k by blocking the openings of all the hollowed portion 6k. The shape of the lid 6e1 may be a shape capable of sealing the opening of the hollowed-out portion 6k, and may be appropriately set according to the shape of the head portion 6d.

The leg portion 6e2 is formed by being bifurcated, and is engaged and fixed when inserted into the hollowed portion 6k. The shape of the leg portion 6e2 is not particularly limited as long as the cover portion 6e1 can be prevented from being detached or rotated. Further, if there is another mechanism capable of fixing the cover portion 6e1, the leg portion 6e2 may be omitted.

As shown in fig. 4, six communication portions (third communication portions) 6i are formed in the head portion 6d in a groove shape in the circumferential direction. The communication portion 6i is formed on the end surface of the head portion 6d, and the end cap member 6e is placed on the head portion 6d to serve as a hole for exhaust. For example, the communication portion 6ia communicates with a hollowed portion 6kc formed in the center and a hollowed portion 6ka formed on the radially outer side thereof. For example, the communication portion 6ib communicates with a hollowed portion 6kc formed in the center and a hollowed portion 6kb formed radially outward thereof.

In addition, four communication portions (second communication portions) 6h are formed in the shoulder portion 6 b. As shown in fig. 6, the communication portion 6h is provided so as to communicate the hollowed-out portion 6k and the trunk portion 6a (inside the tank main body Ta). The shape, number, and the like of the

communication portions

6i and 6h are not particularly limited as long as they can discharge air.

Next, the flow of air during molding will be described with reference to fig. 4 (and also with reference to fig. 5A and 5B as appropriate). For example, air that has entered the communication portion 6ma from the outside of the neck portion 6c is discharged into the tank main body Ta through the hollowed portion 6ka, the communication portion 6ha, and the pillar weight-reducing hole 6g.

For example, the air introduced from the communication portion 6mb of the neck portion 6c is discharged into the tank main body Ta through the hollowed portion 6kb, the communication portion 6ib, the hollowed portion 6kc, the communication portion 6ia, the hollowed portion 6ka, the communication portion 6ha, and the pillar weight reducing hole 6g.

In the present embodiment, the hollow portion 6kc formed in the center communicates with the plurality of communication portions 6i, and thus, for example, air entering from the communication portion 6ma can be discharged from any or all of the communication portions 6ha, 6hb, 6hc, and 6 hd.

Method for manufacturing fuel tank according to embodiment

The fuel tank manufacturing apparatus 1 shown in fig. 7 is an apparatus for manufacturing a fuel tank T (see fig. 1) having a built-in member 6 by blow molding a cylindrical parison S. Further, a sheet-like parison (not shown) may be molded to manufacture the fuel tank T.

As shown in fig. 7, the fuel tank manufacturing apparatus 1 mainly includes: a die head 2; a first molding die 3 and a second molding die 4 which are a pair; and an elevator 5 that moves up and down between the first molding die 3 and the second molding die 4.

The die 2 is a supply unit disposed above the first molding die 3 and the second molding die 4 and configured to supply the parison S to the first molding die 3 and the second molding die 4. The parison S has a multilayer cross-sectional structure formed of HDPE (high density polyethylene), EVOH (ethylene vinyl alcohol copolymer), an adhesive layer, and the like, and is a precursor of the tank main body Ta constituting the fuel tank T (see fig. 1).

The first molding die 3 and the second molding die 4 shown in fig. 7 are molding units for molding the fuel tank T (see fig. 1) in a closed mold. The first molding die 3 and the second molding die 4 are disposed so as to face each other, and

concave molding portions

3a, 4a are formed on the opposing surfaces. The first molding die 3 and the second molding die 4 can be opened and closed by moving in the left-right direction, and the parison S is supplied in a state where the first molding die 3 and the second molding die 4 are opened (a state shown in fig. 7). The first molding die 3 and the second molding die 4 have not-shown blowing bars for feeding air into the first molding die 3 and the second molding die 4, and the air pressure (blow pressure) in the first molding die 3 and the second molding die 4 is appropriately adjusted by a not-shown first positive pressure applying unit. The parison S is transferred to the

molding units

3a and 4a by the first positive pressure imparting unit.

The first molding die 3 is configured to be separated, and includes: a main body 3b; and a separation portion 3c that can be separated from the main body portion 3 b. Similarly, the second molding die 4 is configured to be separated, and includes: a main body 4b; and a separation portion 4c that can be separated from the main body portion 4 b.

Recesses

3d, 4d corresponding to the shape of both end portions of the built-in member 6 are formed in the separating

portions

3c, 4c, and the

recesses

3d, 4d house a part of the built-in member 6. The

recesses

3d, 4d are cylindrical. In addition, a plurality of

air holes

3g, 4g for feeding air into the

concave portions

3d, 4d are formed in the

bottom portions

3f, 4f of the

concave portions

3d, 4d, respectively, and the air pressure (blow pressure) in the

concave portions

3d, 4d is appropriately adjusted by a second positive pressure applying means (not shown).

The lifter 5 is a moving unit that moves the built-in member 6 to the mounting position. The attachment position is inside the cylindrical parison S and between the separating portion 3c and the separating portion 4c.

Next, the operation of the fuel tank manufacturing apparatus 1 will be described. Before explaining all the steps of the method for manufacturing the fuel tank T (see fig. 1) by the fuel tank manufacturing apparatus 1, the transition condition around the end portion of the built-in member 6 will be explained.

< transition condition around end of inner Member >

With reference to fig. 8 and 9 (appropriately, fig. 1 to 7), a transfer state of the parison S around the end of the built-in member 6 at the time of molding will be described. The first molding die 3 is described here, but the second molding die 4 is also similar. The built-in member 6 shown in fig. 8 and 9 shows a state after being cut off at the B-B position of fig. 4.

In the fuel tank manufacturing process, as shown in fig. 8, the first molding die 3 is moved in the arrow direction to close the die, and thereby the neck portion 6c and the head portion 6d of the built-in member 6 are pushed into the recess portion 3d together with the parison S.

As shown in fig. 9, when the shoulder 6b contacts the parison S and covers the opening of the recess 3d and the neck 6c and the head 6d are completely pushed into (accommodated in) the recess 3d, air is introduced into the first molding die 3, so that a positive pressure P1 (first positive pressure) is generated in the parison S, and the parison S is transferred to the first molding die 3. In addition, by feeding air into the concave portion 3d from the air hole 3g formed in the concave portion 3d, a positive pressure P2 (second positive pressure) is generated in the concave portion 3d, and the parison S is transferred while entering the gap 6j between the shoulder portion 6b and the head portion 6d. As described above, the air in the gap 6j is appropriately discharged into the tank main body Ta through the communication portion (first communication portion) 6m, the communication portion (second communication portion) 6h, the communication portion (third communication portion) 6i, the hollowed portion 6k, and the pillar weight-reducing hole 6g.

At this time, the parison S is pressed between the shoulder 6b and the first molding die 3, and the parison S and the shoulder 6b are welded. In addition, the parison S is pressed against the head 6d by the positive pressure P2, and the parison S and the head 6d are welded. Further, by pressing the inner member 6 into the recess 3d, the parison S may be clamped between the head portion 6d and the bottom portion 3f, and thereby the parison S and the end cap member 6e may be welded.

Next, the entire process of the fuel tank manufacturing apparatus 1 will be described.

< procedure for injecting parison >

As shown in fig. 10 (a), the die 2 emits a cylindrical parison S between the first molding die 3 and the second molding die 4 in an open state.

< step of inserting built-in Member >

Next, as shown in fig. 10 (b), the lifter 5 is lifted while holding the built-in member 6, and moves the built-in member 6 to the mounting position. The attachment position is the inside of the parison S, and is between the separation portion 3c and the separation portion 4c.

< temporary Process for setting built-in Member >

Next, as shown in fig. 10 (c), the

separation portions

3c and 4c of the first molding die 3 and the second molding die 4 are moved in the opposite directions, and the built-in member 6 is held so as to be sandwiched from both end sides. Then, the lifter 5 is lowered in a state where the built-in member 6 is released, and retreats to the initial position. The initial position of the lifter 5 may be a position that does not interfere with closing the

main body portions

3b, 4b of the first molding die 3 and the second molding die 4.

< closing Process of Forming die >

Next, as shown in fig. 11 (a), the main body 3b and the main body 4b of the first molding die 3 and the second molding die 4 are moved in the opposite directions, and the first molding die 3 and the second molding die 4 are closed.

< blow Molding Process >

Next, as shown in fig. 11 b, a first positive pressure applying unit (not shown) applies positive pressure P1 (first positive pressure) from the inside of the parison S in the first molding die 3 and the second molding die 4. Thereby, the parison S is pressed against the

molding portions

3a, 4a of the first molding die 3 and the second molding die 4, and transferred. A second positive pressure applying means (not shown) applies a positive pressure P2 (second positive pressure) from outside the parison S in the

concave portions

3d, 4d (see fig. 7) of the first molding die 3 and the second molding die 4. Thereby, the parison S is shaped along the neck portion 6c of the insert member 6 (see fig. 9). The method and sequence for applying positive pressure P1 and positive pressure P2 are not particularly limited. The positive pressure P2 is preferably set higher than the positive pressure P1.

< Cooling Process of parison >

Next, as shown in fig. 11 (C), cooling air C is circulated through the first molding die 3 and the second molding die 4 by using a cooling unit not shown. Thereby, the parison S is cooled and solidified.

< procedure of opening Forming die >

Next, as shown in fig. 11 (d), the first molding die 3 and the second molding die 4 are opened to take out the molded article U. Then, unnecessary burrs formed at both ends are cut, and the fuel tank T (see fig. 1) is completed.

According to the above-described embodiment, the head portion 6d of the built-in member 6 is provided with the end cap member 6e, so that the parison S can be prevented from entering the hollowed-out portion 6k during molding. Therefore, the thickness unevenness of the parison S can be suppressed and the barrier layer can be prevented from being broken or damaged.

Further, since the communication portion 6h is formed in the shoulder portion 6b, the air in the hollowed-out portion 6k can be discharged toward the trunk portion 6 a. That is, the air in the gap 6j can be caused to flow from the communication portion 6m into the hollowed portion 6k, and the air in the hollowed portion 6k can be discharged from the communication portion 6h into the tank main body Ta, so that the exhaust can be reliably performed, and the parison can be reliably shaped around the neck portion 6 c.

Further, since the plurality of hollowed-out portions 6k are formed and the communication portion 6i (third communication portion) communicating with each other with the adjacent hollowed-out portions 6k is formed, the air around the neck portion 6c can be more efficiently discharged to the inside of the tank main body Ta through the communication portion (first communication portion) 6m, the communication portion (second communication portion) 6h, and the communication portion 6i. In particular, in the present embodiment, since the hollowed portion 6kc formed in the center communicates with each of the plurality of communication portions 6i, for example, air entering from the communication portion 6ma can be discharged from any or all of the communication portions 6ha, 6hb, 6hc, and 6hd, and the air discharge efficiency can be improved.

The embodiments of the present invention have been described above, but the design can be changed appropriately without departing from the gist of the present invention. For example, in the present embodiment, the pillar weight reducing holes 6g are formed in a cross-sectional mesh shape, but any shape may be used if the air in the hollowed-out portion 6k can flow into the tank main body Ta. In the present embodiment, the communication portion 6i is provided in a groove shape at the opening end of the hollowed portion 6k, but may be provided as a hole in the same manner as the communication portion 6m and the communication portion 6h. When the communication portion 6i is formed as a hole, it is sufficient to provide the communication portion at any position if the adjacent hollowed

portions

6k, 6k can be communicated.

In the present embodiment, the parison is fixed around the neck by positive pressure from the outside of the parison (blow molding), but the parison may be molded by other molding methods.

Reference numerals

6. Built-in component

6a trunk

6b shoulder

6c neck

6d head

6e end cap component

6m communication part (first communication part)

6h communication part (second communication part)

6i communication part (third communication part)

6k hollowed-out part

S-shaped blank

T fuel tank

Ta box main body

Claims

1. A fuel tank having a built-in member having a head portion, a neck portion, and a shoulder portion, the built-in member being fixed to a tank main body by surrounding a parison around the neck portion when the tank main body is molded,

a hollow part which is opened to the end face side of the head part is formed on the head part and the neck part,

the fuel tank has an end cap member sealing the opening of the hollowed-out portion,

a first communication part which is communicated with the outside and the hollowing part is formed on the neck part,

a second communication portion for communicating the hollowed-out portion with the inside of the case main body is formed at the shoulder portion,

air outside the neck portion flows into the inside of the tank main body through the first communication portion and the second communication portion.

2. The fuel tank of claim 1, wherein,

a plurality of the hollowed-out portions are formed, and a third communication portion communicating with each other is formed adjacent to the hollowed-out portions.